This invention is applied to an audio/video recording/reproduction apparatus. More particularly, the present invention relates to a signal processing device and a signal processing method that can be conveniently used for storing, viewing/listening to and/or retrieving commercial messages added to a television broadcast program.
Conventionally, television and radio programs are normally broadcast with commercial messages (to be referred to simply as CMs hereinafter) provided by one or more than one commercial companies and/or organizations and inserted into the program with few exceptions that may charge a subscription fee.
Some of the viewers of such a program may feel that the CMs are not wanted while other may appreciate them as necessary and direct sources of commercial information particularly when they present famous actors and/or interesting scenes.
However, while the channels and the time slots of television and radio programs to be broadcast can be known in advance by referring to a published time schedule, it is not easy to know in advance the channel and the time slot of a particular CM. Therefore, it may be highly convenient to those viewers/listeners who want to view/listen to particular CMs if the CMs that are broadcast and/or to be broadcast are stored at a particular site so that any viewer/listener who wants to view/listen to a particular CM may access, retrieve and view/listen to it at any time he or she wants.
Japanese Patent Applications Laid-Open Publication Nos. 8-317342, 3-158086 and 3-2622872 proposes techniques for detecting CMs out of broadcast signals so that a viewer/listener can view/listen to a program by skipping the CMs in the program. However, none of the above cited patent documents describe a technique for storing accessing, retrieving and viewing/listening to CMs.
Meanwhile, Japanese Patent Application Laid-Open Publication No. 10-224724 describes a technique of detecting information accompanying CMs, storing the information and replaying a same CM for once. However, the disclosed technique cannot be used to store, access, retrieve and view/listen to CMs. Additionally, the use of the disclosed technique is very limited because it cannot discriminate a stereophonic program and a CM that is broadcast in a stereo mode, although CMs are often broadcast in a stereo mode.
Therefore, there is a strong demand for a technique that can accurately detect CMs out of broadcast signals and also be used for storing, accessing, retrieving and viewing/listening to CMs.